JPS59120998A - Transportion device for gaseous waste processing system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a system for safely and reliably discharging radioactive gaseous waste discharged from a radioactive gaseous waste treatment system Transfer equipment for the radioactive gas waste treatment system (related to 1).

[Technical background of the invention and its problems]

For example, while the coolant (fertility water) in a boiling water reactor passes through the reactor core (under irradiation with two neutrons, part of it is partially decomposed into oxygen and water (2, 'H1 ”NIIft()
etc. nuclides are generated. In addition, trace amounts of K are found in the reactor fuel.
Radioactive rare gases such as r + Xe are generated. These are then mixed with steam and sent to the turbine system.

This radioactive gaseous waste (hereinafter referred to as waste scum) is non-condensable, so it is stored in the steam system, especially in the upper part of the turbine condenser (Niura). Exhaust gas is extracted from the turbine system by an air extractor, and an exhaust gas treatment system is provided to attenuate the extracted exhaust gas until it reaches a specified radioactive concentration and then release it.

In the exhaust gas treatment system, first, the oxygen and hydrogen in the exhaust gas are recombined to form water vapor, and then the water vapor in the exhaust gas is removed using a condenser, dryer, etc. so as not to interfere with the adsorption of activated carbon. Then, after sufficiently attenuating the gas in an activated carbon rare gas hold-up tower (2), it is discharged into the atmosphere using a vacuum pump (2).

As this exhaust gas vacuum pump, a water ring type vacuum pump with a simple structure is generally used from the viewpoint of reliability.

By the way, this vacuum pump is used by circulating seal water, and since the seal water temperature rises, it is operated while being cooled with a heat exchanger, but from the economic point of view
It is normally operated at water temperatures near ℃. Therefore, the exhaust gas vacuum pump discharges exhaust gas at a temperature of 40° C. and a humidity of about 100°C.

In a nuclear power plant, exhaust gas transfer piping is installed running from the exhaust gas vacuum pump to the stack in a trench or other piping for a length of nearly several hundred meters.

During the process of passing through this pipe, the exhaust gas is naturally cooled to the outside temperature of the pipe, but at this time, moisture in the exhaust gas condenses within the pipe. This amount varies depending on the season (changes in outside temperature), but if the outside temperature is around 10 degrees Celsius, in a 1.1 million liter class nuclear power plant, it will be around 2 kilograms in one hour. Usually, treatment equipment is installed at one or two locations in a pipe that is several hundred meters long, so a large amount of wastewater flows endlessly inside a long pipe, which causes problems in terms of maintenance and management. This was a problem in terms of anti-corrosion measures.

In addition, although the temperature was relatively low at 40°C, special care was required in the design of the support structure for the pipes, such as at the @ line portion of the pipes that were several hundred meters long.

The exhaust gas is naturally cooled (up to approximately the same temperature as the outside of the pipe), but the temperature inside the trench is usually higher than that of the outside air, so it depends on the condition of the outside air and the operating status of the plant (up to 2). Therefore, the moisture in the exhaust gas tends to be purified at the stack exit and released into the atmosphere as white smoke, which could damage the image of a nuclear power plant.

The above problems can be solved to some extent by installing a special cooler to lower the temperature of the exhaust gas discharged from the C2 water ring vacuum pump downstream of the water ring vacuum pump. However, it had the disadvantage of making the system unnecessary (and complicated).

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to supply pre-cooled sealed water to a water ring vacuum pump (2) to directly exchange heat with exhaust gas (2). B. To provide a transfer device for an exhaust gas treatment system that eliminates the above drawbacks (there are two types).

[Summary of the invention]

In order to achieve the above object (2), the present invention provides a water ring vacuum pump for transferring exhaust gas generated in a nuclear reactor etc. to the outside through a pipe, and A transfer device for an exhaust gas treatment system having a circulating water tank that separates exhaust gas and sealed water and stores them for sealed circulation use (=); (2) Inside the cooled water-sealed water-ring vacuum pump (2) The exhaust gas is cooled by direct contact with the exhaust gas. Also, the water-seal vacuum pump and the circulating water tank and the circulating water cooler are installed on the same frame.(2) The water temperature of the sealing water is adjusted according to the external atmospheric temperature of the pipe through which the exhaust gas flowing out from the circulating water tank flows. This is how it was done.

[Embodiments of the invention]

Embodiments of the present invention will be described with reference to the drawings.

Figure 1 is an exhaust gas treatment system diagram of the present invention.
The air extractor 2 (outside the turbine system) is extracted, and the recombiner 3 recombines the oxygen and hydrogen in the exhaust gas,
Next, the generated water vapor is condensed in the exhaust gas condenser 4E so as not to interfere with the adsorption of the activated carbon, and then removed in the dryer 5. The exhaust gas is cooled to about -20'C and becomes extremely dry.This dried exhaust gas is passed through activated carbon rare gas hold-up towers 6 and 6, and the radioactive rare gases contained in the exhaust gas are removed. It is adsorbed by the activated carbon and sufficiently attenuated. In this way, the radioactive rare gas attenuated exhaust gas is sent to the exhaust piping by a water ring vacuum pump, passes through the circulating water tank 8, and then goes through the exhaust piping 12. 14 is a part of the exhaust pipe 12 (two connected drain pipes), and 15 is a drain discharge device.

On the other hand, a circulating water pump 9 (
=Therefore, while water is being sent to the vacuum pump 7 (2), circulating water is being sent to the circulating water tank 8 (2) via the flow control valve 18. A cooler 10 is provided, and this cooler 1
0 is a thermometer 17 also provided in the circulating water tank 8
and is connected by an electric wire 16.

The function of the exhaust gas treatment device of the present invention configured as described above will be explained in detail.As mentioned earlier, the exhaust gas extracted from the 1''-1 air extractor 2 is After the oxygen and hydrogen in the exhaust gas are recombined, they are condensed by the exhaust gas condenser 4, and further cooled to -20'C by the exhaust gas dryer 5 (trowel).
The exhaust gas has a dew point of -20℃, and as it flows through the pipes and equipment (= absorbs heat from the outside air, the temperature is about 40℃, the same as room temperature.On the other hand, The temperature of the sealed water supplied from the circulating water pump 9 is controlled at 0°C to 5°C so that it does not freeze, and both the exhaust gas and sealed water are mixed in the vacuum pump 7 (2), The pipe 11 passes through the pipe 11 to the circulating water tank 8 (1).In the circulating water tank 8, due to the cyclone effect, the exhaust gas and water can be separated. The exhaust gas thus cooled to 5° C. to 10° C. is sent to the stack 13 through the exhaust pipe 12.

As explained above (2. According to the exhaust gas treatment device of the present invention (-), the dew point of the exhaust gas is the same as the temperature of the exhaust gas (-56C).
Since the temperature is lowered to ~10°C, the temperature is lower than that of the outside air in the area through which the exhaust pipe 12 passes from then on, and there is almost no condensation in the long pipe up to the stack 13, which has a great effect on preventing corrosion of the pipe. be. This means that whereas in the prior art stainless steel piping should be used, the present invention suffices with carbon steel piping, which has a large cost reduction effect. In addition, in the condensed water of the exhaust gas (2), of course there are daughter nucleons generated by the attenuation of the radioactive rare gas (2), so due to the shielding design, the transfer of condensed water (= requires care, but the condensed water is almost completely Since it can be removed in a concentrated manner, the system can be kept in a healthy state.

Therefore, the operating temperature of the exhaust piping from the storage chamber to the stack can be kept at around room temperature, making it easy to design the piping and support structure. It is also possible to prevent the occurrence of

Further, a decrease in the temperature of the seal water has a very large effect on the performance of the water ring vacuum pump. this is,
This is due to the close relationship between steam pressure and water temperature due to the characteristics of the water-seal structure. In the exhaust gas treatment system, the degree of vacuum required is up to about 250 Hg vacuum, and in this case, it was possible to reduce the output by about 15%. Vacuum pump for Mansode type exhaust gas treatment system (2, 18.5
I was using a pump with an output of about 16 kW, but now a pump with an output of 16 kW is sufficient. Moreover, since the pump is used continuously, this energy saving effect is significant. Moreover, this has the side effect that the amount of heat generated from the pump section is reduced, so that a cooler with a lower capacity can be installed. In addition, (2) Energy saving (=If you pay attention to this, in the past, the pure water produced in-house was conveniently used as make-up water, and about 24 liters of water was discharged into the waste liquid system every hour. (Secondly, the amount of water used and discharged can be reduced and used effectively, resulting in a greater energy saving effect.In particular, in addition to the pure water production process, treatment as radioactive waste liquid (Second) The effects of significant reductions in heating and shrinkage using in-house steam generators and subsequent long-term storage are extremely significant.

In addition, the structure can be made significantly more compact.

In other words, in the past, a water-to-water type heat exchanger was used for cooling circulating water (-), but since it was customary to use a cooling water with a temperature of about 5°C, the heat transfer area was However, in the present invention, the heat exchanger had to be made large, which resulted in a large heat exchanger, but the present invention has made it possible to make it compact.

In addition, the overall size can be reduced by reducing the size of the vacuum bonder mentioned above and the accompanying smaller size of the circulating water pump. In other words, as shown in Figure 2 (2,
In the present invention, the vacuum pump 7, circulating water pump 9, circulating water tank 8, and circulating water cooling device 10 can be combined into one package. Piping connections between each component are made according to the exhaust gas system diagram shown in FIG. In addition, the following effects can be obtained as a side effect by packaging the data in C2 in this way.

i.e. vacuum pump, circulating water pump, circulating water tank,
Since the circulating water cooler and the connecting piping within these devices are packaged together on the same frame and installed as a packaged product, each device can be installed separately (after installation (-1) of the connecting piping) as in the past. There is no need to perform welding. Conventionally, this pipe welding involved fitting work on-site, resulting in extremely poor workability, but with the present invention, such workability is completely improved.

In addition, in the factory as a finished product in a pan-caged state (
2, we can conduct sufficient tests such as leak tests, pressure tests, performance tests, etc., and we are able to guarantee a higher purchase price compared to conventional methods. I had no choice.

Furthermore, the conventional equipment layout was determined by taking into consideration the workability of equipment connection piping at the site (-1).
It needed a lot of space. According to this embodiment,
Since such piping is already installed as a packaged product, there is no need to consider the space for two pairs of windows during on-site work, and the savings in installation space are enormous.

In addition to the above, a noteworthy feature is that the on-site construction period can be significantly shortened.

Figure 3 shows another embodiment of the present invention, which is the same as Figure WJ1 (2 is given the same reference numeral).

In a nuclear power plant, while the exhaust gas passes through piping in the trench from the exhaust gas vacuum pump 7 to the stack 13 (2. It is already known that the exhaust gas is naturally cooled to the outside ambient temperature (= the embodiment shown in Figure 1 (2)). I have just explained this, but as shown in Figure 3 (it is easy even if there are two), the exhaust gas that remains in the turbine condenser 1 (2) is extracted from the turbine system (=extracted from the air extractor 2 (2) and transferred to the recombiner). In step 3, the oxygen and hydrogen in the exhaust gas are recombined to produce water vapor, which is then condensed in the exhaust gas condenser 4 (secondary) and removed in the dryer 5. It is cooled to a very low temperature (
It will be in a dry state. This exhaust gas passes through the hold up tower 6, is introduced into the exhaust pipe 11 by the vacuum pump 7, passes through the circulating water tank 8, passes through the pipe 12, and is discharged from the stack 13 into the atmosphere. As shown in Figure 3, the temperature of the indoor atmosphere when the two outdoor trenches are added is measured by the thermometer 2.
The set temperature of the cooling device 10 is changed through the regulator n and the stain line, and the temperature of the circulating water in the circulating water tank 8 is changed. In this way, the circulating water whose temperature has been changed is circulated by the circulating water pump 9 (secondly, the vacuum pump 71).
The temperature of the exhaust gas at the outlet of the vacuum pump is changed. This method aims to raise the temperature of the exhaust gas to such an extent that condensation does not occur in the piping 12 (2), and to save the power consumed by the cooling device 10 (2), allowing for rational operation. be.

FIG. 4 shows a piping system diagram of the exhaust gas vacuum pump 7 and the circulating water tank 8 and 9, and shows the same parts as FIGS. 1 to 3. (- is given the same symbol. That is, as shown in the figure (=, sealed water is sent from the lower part of the circulating water tank 8 by the circulating water bonder 9 via the circulating water cooler 5 to the vacuum pump 7 (1). With (
Circulating water is supplied to the circulating water tank 8 (1
Sent. The circulating water cooler 5 is connected to the refrigerant piping and the cooling device moss, and the thermometer 29 provided on the outlet pipe side C2 of the circulating water cooler 25 and the cooling device 27 are connected to the electric line. Therefore, in this embodiment, the temperature of the circulating water is detected by the thermometer 290 and transmitted to the cooling device 27.
The circulating water cooler 25 (2) is controlled with high precision. It has.In addition,
The exhaust gas that has passed through the pipe 12 from the circulating water tank 8 is released into the atmosphere from a stack (not shown).

〔Effect of the invention〕

According to the present invention (=), the operation of the vacuum pump can be made healthy, the energy saving effect is large, and the entire device can be made compact.Moreover,
The practical effects, such as shortening the on-site construction period, are significant.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an exhaust gas treatment system according to an embodiment of the present invention.
FIG. 2 is a perspective view of the package of the circulating water tank shown in FIG. 1, FIG. 3 is a system diagram of an exhaust gas treatment system according to another embodiment of the present invention, and FIG. Example (1) It is a system diagram of the piping system of the circulating water tank according to 1. Turbine raw condenser, 2... Air extractor 3...
・Recombiner, 4... Exhaust gas pumper 5... Exhaust gas dryer, 6... Rare gas hold rough column 7... Vacuum pump, 8... Circulating water tank 9... Circulating Water pump, 10.27... Circulating water cooling device 13... Stack, 17.21.2
9...Add thermometer...Outdoor trench, %...
Adjuster (8733) Agent Patent Attorney Yoshiaki Inomata (
(1 other person) Figure 1 Figure 2 Figure 3 Figure 4

Claims (3)

[Claims] (1) A water ring vacuum pump for transporting radioactive gaseous waste generated in nuclear reactors, etc., and downstream of this vacuum pump (=
In a transfer device of a gaseous waste treatment system having a circulating water tank for storing the gaseous waste and the sealed water, and for separating the gaseous waste and sealed water and using the circulating water in a sealed manner, Gaseous waste treatment characterized by cooling the gaseous waste by bringing the cooled sealed water into direct contact with the gaseous F!Az substance in the water-sealed vacuum bong. System transfer device. (2) The water temperature of the sealing water is controlled according to the external ambient temperature of the pipe through which the gaseous waste flows out from the circulating water tank (1). (3) The transfer device for a gaseous waste treatment system according to claim 1, wherein the water ring vacuum pump, the circulating water tank, and the circulating water cooler are arranged on the same frame.